[Ocfs2-users] debugfs.ocfs2 and Feature Incompat

[Sunil Mushran]

Are you having any problems using the software?

On 06/01/2010 10:55 AM, Stefan Priebe - allied internet ag wrote:
> Hi!
>
> Thanks for your answer but i'm still a little bit confused.
>
> I'm running ocfs2 tools git HEAD (middle of may) on each machine with 
> a 2.6.32.12 kernel. Also the disk was formatted using:
> mkfs.ocfs2 --fs-feature-level=max-features -L ocfs2disk -N 10 -T mail 
> -v /dev/sdb
>
> So i thought that i can now use features like unwritten, inline-data 
> and indexed-dirs.
>
> Stefan
>
> Sunil Mushran schrieb:
>> On 06/01/2010 04:06 AM, Stefan Priebe - allied internet ag wrote:
>>
>> <snip>
>>>           Feature Compat: 3 backup-super strict-journal-super
>>>           Feature Incompat: 8016 sparse extended-slotmap inline-data
>>> metaecc xattr indexed-dirs refcount
>>>           Tunefs Incomplete: 0
>>>           Feature RO compat: 1 unwritten
>>>
>> <snip>
>>
>>> But why is inline-data, indexed-dirs and so on incompatible?
>>
>> incompat means that a version of the fs not aware of this feature
>> should not mount the fs. And that fsck should abort. Users encountering
>> this error need to mount the fs with a newer version of the fs. Or, use
>> tunefs.ocfs2 to disable that feature.
>>
>> Similarly, ro compat features means that a version of the fs not aware
>> of the feature can mount fs in read-only mode only.
>>
>> As to which feature is incompat/ro/compat is a function of the disk 
>> format
>> change involved. Changes that do not negatively affect the 
>> functioning when
>> mounted with an older version are "compat". Changes that will corrupt 
>> the
>> fs if mounted with an older version are "incompat". "ro compat" are 
>> changes
>> that will work as long as the older fs does not write to it.